CdZnTe material is an indispensable substrate material for the preparation of high-performance HgCdTe infrared focal plane detectors. The liquid phase epitaxy and the molecular beam epitaxy require the use of (111) and (211) CdZnTe substrates to prepare HgCdTe thin-film materials, respectively. The selection of low off-angle and high-precision substrates is conducive to the acquisition of high-quality HgCdTe epitaxial layers.The twin line rapid orientation method，the X-ray diffractometer orientation method to determine the (111) crystal plane of the CdZnTe crystal, and the method of obtaining (211) CdZnTe from (111) CdZnTe by X-ray diffractometer are introduced. The research results are of great sigificance to the development of high-performance HgCdTe detectors.